<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-values-4/#comp-func">
<link rel="author" title="Xiaocheng Hu" href="mailto:xiaochengh@chromium.org">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../support/computed-testcommon.js"></script>
<div id="container" style="font-size: 20px">
  <div id="target"></div>
  <div id="reference"></div>
</div>
<script>
const property = 'letter-spacing';

function test_length_equals(value, expected) {
  const reference = document.getElementById('reference');
  reference.style[property] = '';
  reference.style[property] = expected;
  const computed = getComputedStyle(reference)[property];
  test_computed_value(property, value, computed);
}

test_length_equals('clamp(10px, 20px, 30px)', '20px');
test_length_equals('clamp(10px, 5px, 30px)', '10px');
test_length_equals('clamp(10px, 35px, 30px)', '30px');
test_length_equals('clamp(10px, 35px , 30px)', '30px');
test_length_equals('clamp(10px, 35px /*foo*/, 30px)', '30px');
test_length_equals('clamp(10px /* foo */ , 35px, 30px)', '30px');
test_length_equals('clamp(10px , 35px, 30px)', '30px');

// clamp(MIN, VAL, MAX) is identical to max(MIN, min(VAL, MAX)),
// so MIN wins over MAX if they are in the wrong order.
test_length_equals('clamp(30px, 100px, 20px)', '30px');

// also test with negative values
test_length_equals('clamp(-30px, -20px, -10px)', '-20px');
test_length_equals('clamp(-30px, -100px, -10px)', '-30px');
test_length_equals('clamp(-30px, 100px, -10px)', '-10px');
test_length_equals('clamp(-10px, 100px, -30px)', '-10px');
test_length_equals('clamp(-10px, -100px, -30px)', '-10px');

// and negating the result of clamp
test_length_equals('calc(0px + clamp(10px, 20px, 30px))', '20px');
test_length_equals('calc(0px - clamp(10px, 20px, 30px))', '-20px');
test_length_equals('calc(0px + clamp(30px, 100px, 20px))', '30px');
test_length_equals('calc(0px - clamp(30px, 100px, 20px))', '-30px');

</script>
